Journal of Physical Chemistry B, Vol.103, No.35, 7522-7530, 1999
Deviation from corresponding states for a fluid of square well spherocylinders
The nonconformal behavior of a fluid of hard spherocylinders with a spherocylindrical square well attraction is examined using a simple perturbation theory in which the thermodynamics of the anisotropic fluid is mapped to that of an equivalent spherical system. This theory was shown to give a good description of the thermodynamic properties of the isotropic phase of a fluid of hard core aspect ratio 5:1 and square well range lambda = 1.5. To date no simulation data exists for the vapor-liquid region of this model; however, the theoretical predictions are compared with Gibbs ensemble Monte Carlo simulation data for the linear Kihara potentials. A strong similarity is observed. in the phase behavior of both fluids. The square well system has the advantage that there is a good theoretical equation of state in which the range parameter can be varied without extra computational difficulty. Finally, despite the simplicity of the square well model, we demonstrate that this model can be used to describe the vapor-liquid coexistence of the alkane chain series from ethane to octane.